Update failed, assistance needed

I use 7.10 version of Ubuntu. When I was updating my Ubuntu, my internet line break away per minute. Now I can't update my version and my computer is become slowly and Ubuntu gives this warning;

E: dpkg was interrupted, you must manually run 'dpkg --configure -a' to correct the problem.
E: _cache->open() failed, please report.

I cant use black screen(like a DOS screen). What will I do?

Thank you for your care.

H. Volkan UNAL
Turkey